One basic type of platform scale has a weighing platform supported on a lever mechanism which converts a small deflection under load to a large scale useful readout. The lever mechanism comprises a pair of T-shaped levers, each of which is suspended from a supporting frame by the cross bar portion of the T. The stem portions of the levers overlap and are pivotally interconnected, one stem extending for connection to the readout means. Various pivotal suspension means have been used, such as hooks with loops or notched portions engaging pins or knife edged members.
This type of mechanism is suitable for mechanical readout means, using a rotating pointer or a beam with adjustable weights. However, with an electronic readout system, particularly the digital type, the mechanism is not sufficiently accurate to use the full potential of the readout. The basic problem is that the suspension means has little or no provision for adjustment. Certain of the pins, hooks, knife edges and other elements are fixed in the frame structure for convenience and simplicity of manufacture. Due to necessary manufacturing tolerances, some of the linkages may not hang truly vertical or in proper alignment. As a result, there may be undesirable offset loads and drag on the mechanism under varying load conditions which, due to the magnified readout, can cause a substantial discrepancy in the indicated weight.